1. Field of the Invention
This invention relates generally to the art of sorting and categorizing materials and, more particularly, to a subsystem for use with a multi-station sorter incorporating a display array and a printer array for dynamically variably assigning, identifying or designating information of the materials transferred to each station. The subsystem is described with particular reference to the postal sorting operations.
2. Description of the Related Art
The problems of sorting and handling large amounts of material are best exemplified by the postal service. In order to handle and sort efficiently very large volumes of mail, central post offices in large cities typically employ diverse sorting equipment in which the sorting function is based on reading the zip code provided as a suffix to the address set forth on a letter or package. In some sorting equipment, the zip code is visually read by an operator and manually entered from a keyboard as each piece of mail passes in front of the operator. This system, in the more highly automated post offices, is now used principally to sort mail for which more sophisticated electronic zip code readers have been unable to decipher the zip code. Thus, much of the mail is sorted through machines which incorporate optical character reading capability for either undertaking to read directly the Arabic numerals representing the zip code on a piece of mail or reading a previously provided bar code (as in mass commercial mailings) to effect the mail sort by zip code. Some sorting machines have the facility for selectively performing either sorting function, and some also have the facility for dynamically entering a bar code on a piece of mail as a result of successfully reading the Arabic numbers of the zip code. This technique increases the efficiency of the subsequent handling of that piece of mail because a bar code is most reliably read by electronic zip code readers.
Those skilled in the mail handling arts will appreciate that each piece of mail typically undergoes multiple sorts, particularly at the main post office of the point of destination, but also at the main post office of the point of origin and even at subsidiary post office stations. Further, and particularly relevant to the subject invention, those skilled in the art will also appreciate that the same sorting machines may be employed to sort at different levels during different sort sessions conducted throughout the working day. That is, an afternoon sort may be undertaken which is "finer" than an earlier sort carried out on the same machine in order to sort the run of mail down to (merely by way of example) an individual carrier. The mail may have been previously sorted to an individual substation by a preceding sort which might have been carried out a few hours earlier during a different phase of the operation day.
During the operation of a sorter, each piece of mail is physically routed to one of many stations according to the sensed zip code. The letter mail sorted to each station is periodically picked up and placed into a more or less standard "managed mail tray". Concurrently with that step, an encoded "slip label" is placed into a transparent pocket situated on the forward end of the managed mail tray to convey significant information relevant to the manner in which the mail in the particular tray should be handled during a subsequent sort at the same or a different post office.
Because of the multiple sorts at different levels which may be undertaken on a given sorting machine, it is necessary to provide a visual indication for the zip code assigned to each station for the sort currently underway. This feature is required to direct the person transferring the mail sorted to a given station into a managed mail tray to select the correct slip label for insertion into the pocket of the managed mail tray. In the past, this function has been undertaken by more or less clumsy expedients such as by simply using several different color coded labels permanently emplaced at each station. The person effecting the transfer of the mail to the managed mail tray relied on memory and on routine to recognize which zip code is being currently sorted to a given station. As well as being unreliable, this approach rigidly limits the flexibility of assigning diverse zip codes to each station of a sorter. Thus, those skilled in the mail handling arts will particularly well understand that it would be highly desirable to provide a single, easily readable and completely flexible display which, at all times, correctly indicates the zip code of mail currently being sorted to a given sorter station.
In the past, each station has had preprinted labels for insertion in the pocket of the mail tray. In practice, the preprinted labels have tended to be inadvertently removed from the storage locations and have frequently not been available when needed. In addition, care had to be taken to insure that the correct label (of several available preprinted labels for any given station) was inserted in the tray pocket. Therefore, it would be highly desirable to provide a printer proximate a sorting station that would print labels on demand having the information provided by the display defining the sort criteria.
Therefore, a need has been felt for a subsystem having a single easily readable and flexible display which, at all times, provides the correct information concerning the associated station and for a printer that can prepare a label with that information of the display on demand.